The present invention relates to a textile treating composition containing amino-modified silicone oils.
Linear polysiloxanes, so-called silicone oil, have been broadly employed in textile treating compositions for acrylic fibers which are processed into clothings or applied as the precursor in carbon fiber production, because of the water repellency, detachability, heat resistance, peculiar handle, i.e., smoothness or slickness, which are imparted to fiber by silicone oil. Particularly, the linear amino-modified polysiloxanes having amino groups in their molecules have proved superior performance as a component of textile treating compositions for acrylic fibers for clothing or for the precursors of carbon fibers. Because the linear amino-modified polysiloxanes can be dispersed into fine globules with suitable emulsifiers.
Amino-modified polysiloxanes have also proved superior performance as a textile treating agent for preventing the fusion or adhesion of organic and inorganic fibers in heat treatment, because of their detachability and heat resistance. The fusion or adhesion of fibers results in poor fiber quality.
Many processes for applying textile treating compositions containing amino-modified polysiloxanes to fibers have been proposed in literature, such as Japanese Patent KOKOKU (Publication for opposition) No. Sho. 52-24136, Japanese Patent KOKAI (Provisional Publication) No. Sho. 62-45786 and No. Sho. 62-45787, Japanese Patent KOKAI No. Hei. 6-220722 and No. Hei. 6-220723 and others.
Amino-modified polysiloxanes can be dispersed into fine globules of 0.1 micrometer or less in diameter in an aqueous emulsion with the aid of an emulsifier having acidic groups. The fine globules are attained by the hydrophilic amino salts generated from the reaction of basic amino groups in the amino-modified polysiloxanes and acidic groups in the emulsifiers blended with the amino-modified polysiloxanes. The above aqueous emulsion is almost transparent, and thus the amino-modified polysiloxanes seem to have been dissolved. Actually, however, they are dispersed into fine globules of approximately several decades of milimicrometer giving high transmittance to the resultant emulsion.
Such fine globules of textile treating composition dispersed in aqueous emulsion are preferable for applying the textile treating compositions uniformly on fiber surface.
Such fine globules are indispensable for applying textile treating compositions rapidly to the surface of monofilaments located at the inside of tows or multifilament yarns.
The finish film on fiber attained by a textile treating composition dispersed in fine globules in aqueous emulsion is much more uniform than that attained by the textile treating compositions dispersed in coarse globules to give milky emulsion. Uniform finish film minimizes the decrease or variation of water repellency, detachability, heat resistance, and peculiar handle of fiber, i.e., smoothness and slickness.
Japanese Patent KOKAI No. Hei. 6-220722 and No. Hei. 6-220723 disclose that amino-modified polysiloxanes applied on fiber gradually degrade into smaller molecules during storage, due to the breakage of the molecular chain of the amino-modified polysiloxanes, when the amino-modified polysiloxanes are prepared into emulsion with the emulsifiers having acidic groups disclosed in Japanese Patent KOKOKU No. Sho. 52-24136, and Japanese Patent KOKAI No. Sho. 62-45786 and No. Sho. 62-45787. And the above KOKAI No. Hei. 6-220722 and No. Hei. 6-220723, also disclose that the heat durability, detachability, and peculiar handle imparted by the amino-modified polysiloxanes are gradually reduced due to the degradation.
The methods for solving the above problem are proposed in Japanese Patent KOKAI No. Hei. 6-220722 and No. Hei. 6-220723, in which amino-modified polysiloxanes are emulsified with nonionic emulsifiers and weak carboxylic acids instead of strongly acidic emulsifiers.
The inventors of the present invention found that the textile treating compositions disclosed in the prior art mentioned above are apt to fall from fiber to stick on the surface of guides and rolls employed in yarn-spinning or textile dyeing processes of acrylic fibers, and in the conversion processes of polyacrylonitrile precursors into carbon fibers.
The textile treating compositions sticking on the guides or rolls change into varnish type residue to cause the wrap of monofilaments of tows during long-time continuous processing. Further, the dusts in a workplace stick on the varnish type residue on the guides or rolls, causing monofilament breakage and fluffs.
A method for preventing the guides and rolls from the adhesion of textile treating compositions by adding various antioxidants has been proposed in Japanese Patent KOKAI No. Hei. 2-91225. The method may often result in the reduction of the durability of the water repellency, detachability, heat resistance, and peculiar handle imparted to fiber, though the method may prevent the varnish type residue on the guides or rolls. The antioxidants proposed in the above method are estimated to decompose amino-modified polysiloxanes into smaller molecules so as to reduce the chemical stability of the amino-modified polysiloxanes, though the antioxidants prevent the gelling of the amino-modified polysiloxanes. The function of the antioxidants, the acceleration of the decomposition of dimethylpolysiloxane into smaller molecules is described in Zh. Prikl. Khim. Vol. 49, No. 4, p 839-844 (1976).
The proper level of the gelling of amino-modified polysiloxane is preferable for attaining durable water repellency, detachability, heat resistance, and peculiar handle of the fiber. Some of the textile treating compositions comprising amino-modified polysiloxanes emulsified with phosphoric esters and blended with antioxidants cannot attain durable water repellency, detachability, heat resistance, and peculiar handle on fiber.
Antioxidants, strongly acidic substances, and basic substances, all of which minimizes the gelling of amino-modified polysiloxanes, may decompose amino-modified polysiloxanes into smaller molecules during long-term storage or heat treatment leading to the reduction of heat resistance of amino-modified polysiloxane.